To get around the "time consuming" issue, this would be my suggestion, if you did want to branch into the idea of different characters each undertaking their separate objectives:

You spend a lot of, say, LQ 2 with the women B2P'ing in different locations, without much variance in any other aspect (other than maybe the loudness of the sound effects). "Let's B2P in a cave, then in a house, then in a park, then in a tent, then in another cave." This probably leads a lot of time-consuming dialogue and sprawling rendering of graphics. Maybe instead your focus would be, say, just 4 main screens, with (say) 12 tasks for whatever character you choose. "Your goal is to avoid as many bangs as possible, or take as little of the brunt of as many of the bangs you do hear as possible." "Your goal is to trap and scare 4 different phobic women or the same phobic woman 3 times." "Your goal is to pop a balloon in all 8 locations before your rival does." So the scope of the game would be "smaller" but more interesting, and there'd be a way to "win" with each character if you undertook the correct steps. And "Kim," who is phobic, might interact with "Heather," who loves scaring other girls, in multiple scenarios, but if you're controlling Kim or if you're controlling Heather, or if you're controlling Diane, who is simply observing Heather and Kim interact, your objective would be different, so the scenario may end differently.